Long-term Outcome of Azathioprine Versus Mycophenolate Mofetil in Cyclosporine-Based Immunosuppression in Kidney Transplantation: 10 Years of Experience at a Single Center

Abstract Background Mycophenolate mofetil (MMF) has been used worldwide as part of maintenance immunosuppression since initial large cyclosporine-based trials reported that compared with azathioprine (AZA), MMF reduced acute rejection episodes after renal transplantation. However, long-term benefits of MMF have not been established; the follow-up period of previous studies was within 5 years. The aim of this study was to compare the acute rejection rates, allograft function, and graft and patient survivals of these 2 drugs in conjunction with cyclosporine and steroids over a period of 10 years. Methods We reviewed recipients who had undergone kidney transplantation from January 1998 to January 2002. Eighty-six patients were divided into 2 groups (MMF = 43, AZA = 43). All patients received cyclosporine and steroids concomitantly as maintenance immunosuppressive therapy. Results Baseline characteristics were similar between the 2 groups except donor type. Multiple logistic regression analysis showed MMF therapy to reduce the acute rejection rate in the first 12 months after transplantation (relative risk [RR], 0.181; 95% confidence interval [CI], 0.035–0.936; P = .042). Cox proportional hazard analysis revealed MMF to was not associated with improved graft and patient survival. Graft function was comparable between the 2 groups over 10 years. No significant differences were observed in the incidence of serious infections or malignancy. Conclusions Compared with AZA, MMF offered the clinical benefit of prevention of acute rejection episodes, but displayed similar effects on long-term graft and patient survivals in kidney transplant recipients undergoing cyclosporine-based immunosuppression.